Reamer



(No Model.)

P. E. SHIRK.

'REAM'ER.

UNi'rnn ST TES PATENT OFFICE.

PETER E. SHIRK, OF SPRING GROVE, ASSIGNOR TO XVILLTAM H. LAWSON,

/ OF HONEYBROOK, PENNSYLVANIA.

REAM ER.

SPECIFICATION forming part of Letters Patent No. 308,707, dated December 2, 1884.

Application filed December 8,1883. (No model.)

T at whom it may concern/.-

Be it known that I, PETER E. SHIRK, of

Spring Grove, in the county of Lancaster and State of Pennsylvania, have invented certain Improvements in Reainers, of which the following is a specification.

My invention relates to reaming or counterboring tools of peculiar construction adapted more particularly for use in iron, steel, and

brass.

Referring to the accompanying drawings, Figure 1 represents a side elevation of my improved reainer. Fig. 2 is a view looking against the cutting end of the same. Fig. 3 is a cross-section on the line 00 m. Fig. 4. is a cross-section on the line 2 .2. Fig. 5 is a longitudinal central section on the line y As represented in the drawings, the reamer has its principal portion or shank made of a straight flat form. The middle portion of its length is made of a twisted or fluted form with two flutes or convolutions, c, on opposite sides. The point or cutting end of the tool has in cross-section the form produced by cutting four spiral grooves or channels, d, longitudinally in the outer surface of a cylinder. The rear walls of these channels rise radially, or substantially so, from the center of the tool, so as to present sharp cutting-edges c. It will be observed that two of these cutting-edges form continuations of the edges of the twisted portion Z). The channels (1 are-carried downward and extended inward across the point of the tool toward the center, as represented in 3 5 the drawings, particularly Fig. 2, thus producing cutting-edges c at the end'of the tool. At the cutting end the body is provided with a centralhole or recess, 9, with which the channels before alluded to communicate. Thetool 4.0 may have its upper portion slightly tapered or diminished in size toward the shank, in order to avoid friction; but this is not necessary, and in any event the taper should be very slight. The forward or cutting end is made of a con- 5 stant diameter on the outside, in order to fit that it will be guided in a right line and prevented froni swerving to the right or left.

In practice it is found that a reamer constructed as above may be operated with great 0 rapidity by a moderate degree of power and without danger of choking when driven at 7 high speeds. It is also advantageous in that it is adapted to finish holes in a true cylindrical forin. 5 5

The tool may be forged from the solid, or formed from a blank twisted at the upper end and upset or enlarged at the lower end, various modes of procedure by which such a tool may be constructed being perfectly familiar to 6c persons skilled in the art.

Having thus described my invention,,what I claim is-- 1. The reanier haying the otherwise cylindrical point provided with the grooves or channels (1, extended in a spiral direction in its exterior surface, and then inward at the end toward the center.

2. The reamer having the cutting-edges e and e in the form described and shown, and the fluted portion 0.

3. A reainer having the flat shank a, the fluted portion 0, and the otherwise cylindrical point with channels d in its periphery and in its end, substantially as described and shown. 7

4. The manner having the central recess in its end, and the grooves or channels extended through said recess to the periphery, and thence upward inaspiral direction within-the periphery, said parts being constructed in the form described and shown.

5. In a reamer, the portion 1), having two spiral flutes, c, in opposite sides, and having the forward end of otherwise cylindrical form provided with four grooves or channels, (I, therein, the walls of two of these channels forming a continuation of the edges of the portion b.

PETER E. SHIRK.

WVitnesses:

' J Essn I. DAUMAN,

ELwoon M. LUDWIGK. 

